/Engine/Plugins/Runtime/GeometryProcessing/Source/DynamicMesh/Public/Operations/IntrinsicCorrespondenceUtils.h
Update the signpost after an edge flip. This requires information about the both the pre and post flip state.
void OnFlipEdge ( const int32 EID, const [FIndex2i](API\Runtime\GeometryCore\FIndex2i) AdjTris, const [FIndex2i](API\Runtime\GeometryCore\FIndex2i) OpposingVerts, const [FIndex2i](API\Runtime\GeometryCore\FIndex2i) PreFlipIndexOf, const double Opp0NewInternalAngle, const double Opp1NewInternalAngle )